Method of making multistrand textile cord



Dec. 2, 1969 R, WHEWELL, JR

I METHOD OF' MAKING MULTISTRAND TEXTILE CORD Filed Jan. 19, 1968 ATTORNEYS United States Patent O U.S. Cl. 57-160 2 Claims ABSTRACT OF THE DISCLOSURE Seven-end textile cord is made on a 2-for-1 twisting machine by pre-twisting the central strand about its own axis in a predetermined twist direction, pre-twisting each of the outer strands about its own axis in the opposite direction and, in the machine, twisting the outer strands in said predetermined twist direction helically about the central strand as a core.

This invention relates to a method of making multistrand textile cord having a plurality of outer strands twisted around a central strand.

In the use of certain high speed 2-for-l twisting and winding machines for twisting several textile strands into a cord and winding the cord into a sales package, a serious ditiiculty encountered heretofore has been the occurrence of kinks or blips in the finished cord. Particularly in the case of seven-end textile cord having a central strand surrounded by six outer strands, it was considered previously that such imperfections could not be eliminated from cord produced by such machines. The present invention completely eliminates this difliculty by pretwisting the individual strands in a particular novel manner before the strands are twisted together in the machine to form the final multistrand cord'.

It is a principal object of this invention to provide a novel and improved method of making multistrand textile cord on a 2-for-l twisting machine by twisting the outer strands around a central strand which is pre-twisted about its own axis in the same twist direction as the outer strands are twisted about it, with each outer strand being individually pre-twisted about its own axis in the opposite twist direction.

Another principal object of this invention is to provide a novel and improved method of making multistrand textile cord on a 2-for-l twisting machine which eliminates the tendency for the central strand to migrate to the outside of the cord and to prevent a kink or the like projecting laterally beyond the outer strands of the cord.

Another object of this invention is to provide such a method which has novel provision for insuring that the central strand will be taut while the outer strands are being twisted around it in the 2-for-1 twisting machine, thereby insuring that the central strand does not produce kinks or the like projecting outside the outer strands.

Another object of this invention is to provide such a method which makes possible the use of high speed, 2- for-l twisting machines to produce seven-end cords which is substantially free of such imperfections.

Further objects and advantages of this invention will be apparent from the following description, with reference to the accompanying drawing in which:

FIGURE l illustrates schematically a known type of high speed 2-for-l textile twisting and winding machine which may be used to produce multistrand textile cord in accordance with the present invention;

FIGURE 2 is a view illustrating schematically how seven individually pre-twisted textile strands are twisted together to provide seven-end cord in accordance with the method of the present invention;

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FIGURE 3 is a cross-section through the seven-end cord; and

FIGURE 4 illustrates a short length of seven-end cord having an imperfection in the form of a kink whose occurrence is prevented in accordance with the method of the present invention.

FIGURE 1 illustrates schematically a known type of textile yarn twisting and winding machine which may be used to produce multistrand textile cord in accordance with the present invention. This 2-for-1 twisting machine is basically similar to the machine disclosed in United States Letters Patent No. 2,830,431, which may be referred to for a more detailed description of the construction and operation of the machine.

In the operation of the machine in accordance with the known practice, individual strands or ends of textile material are withdrawn under suitable tension from packages or cones on a creel (not shown) and they pass through respective openings in a multiple-eyelet separator guide or holly board 10. In the particular example shown, there are seven strands or ends which go to make up the finished cord, a central strand and six outer strands, all of substantially the same diameter. After passing through the separator guide 10 the individual strands converge toward each other and pass through a compression-type forming guide 11. As the strands emerge from the outlet (right) end of the forming guide, the six outer strands O are grouped in succession circumferentially around the central strand C, as shown in FIG. 3.

The grouped strands pass axially through a hollow motor-driven rotary spindle 12 and out through an outlet opening in the periphery of the spindle and across the surface of a yarn storage or wrap-around member 13 and from there outwardly across a generally cup-shaped flyer disk 14. The wrap-around member 13 and the iiyer disk 14 are attached to the spindle 12 for rotation in unison with it.

Due to centrifugal force the grouped strands balloon outwardly as they advance across and beyond the flyer disk 14. At the opposite end of the machine, the grouped strands pass back through an apex guide 15.

For each rotation of the spindle and tlyer disk, two complete twists are imparted to the six outer strands O, so that they are twisted helically around the central strand C as a core. Each outer strand is wrapped tightly about the central strand and contacts the latter along a continuous helical path, and the outer strands intert helically with each other to completely enclose the central strand. The first twist occurs ahead of the outlet opening in the spindle 12. The second twist (in the same direction) occurs between the strand outlet opening in the spindle 12 and the apex guide 15.

After the twisted seven-strand cord emerges from the apex guide 15, it passes over an idler pulley 16 and makes several turns around a double capstan 17, 18. From the double capstan the cord passes over an idler pulley 19, across a pulley 20 attached to a tension-compensating spring 21, and over a series of pulleys 22, 23, 24, 25 and 26 to a traverse guide arm 27. The cord passes through an opening 28 in the traverse guide arm onto the sales package of cord wound up on a rotary core 29. The traverse guide arm 27 is reciprocated, such as by a mechanism as shown in the aforementioned U.S. Patent 2,830,- 431, back and forth along the length of the core 29 as the cord is wound up progressively on the latter. The pulley 24 is reciprocated back and forth opposite to the movement of the traverse guide arm 27 so as to compensate for the latters changing lposition with respect to the double capstan 17, 18.

Prior to the present invention considerable difficulty was encountered in using high-speed winding machines of this general type to produce multi-strand cords, particularly seven-end cord of the type shown in FIG. 3. It was found that imperfections in the form of blips or small kinks frequently occurred in such cord, not only spoiling its appearance but also making it unsatisfactory for certain uses. FIGURE 4 illustrates a short length of seven-end cord having such a kink 30 protruding laterally beyond the outside surface of the cord. This kink is formed in the central strand C in the cord, and Vprior to the present invention it was thought to be impossible to eliminate such imperfections in seven-end cord produced by a twisting machine operating on the 2-for-l principle (i.e., two twists of the cord for every revolution of the spindle and flyer disk).

I have discovered that this difculty can be overcome by using strands which have been individually pre-twisted in a particular novel manner with respect to the direction in which the twisting machine will twist the outer strands about the central strand as a core to provide the finished multistrand twisted cord. In accordance with my invention, the central strand C is pre-twisted about its own axis in the same twist direction as the outer strands O are to be twisted about it by the twisting machine, while each of the outer strands O is pre-twisted about its own axis in the opposite twist direction. If the machine puts an S-twist in the multistrand cord, the central strand will be pre-twisted with an S-twist and each of the outer strands will be individually pre-twisted with a Z-twist. Conversely, if the machine puts a Z-twist in the multistrand cord, the central strand will be pre-twisted with a Z-twist and the outer strands will be individually pretwisted with an S-twist. As shown in FIG. 2, where the outer strands of the multistrand cord Y are to be twisted about the central strand as a core in a direction clockwise to the right, before the strands enter the machine, the central strand C will be pre-twisted in the same twist direction and each outer strand O will be pre-twisted in the opposite twist direction. The seven individually pre-twisted strands C and O pass through the separator board and then are twisted by the machine of FIG. 1 to provide the Vfinished seven-end cord Y in FIG. 2.

It is believed that the elimination of kinks, blips or similar imperfections in the multistrand cord in accordance with the present invention is due to the following action which takes place as the Winding machine is twisting the outer strands about the central strand as a core:

As the winding machine puts the second twist in the cord (for each rotation of the spindle and yer disk), it tends to tighten or contract the turns of the central strand `C because the direction in which the central strand C is pre-twisted is the same as the direction in which the outer strands O are being twisted about the central strand C as a core. At the same time, the pre-twisted turns of each of the outer strands O tend to separate or expand because the direction in which the outer strands have been pre-twisted individually is opposite to the direction in which the machine is twisting them helically around the central strand C as a core. Consequently, there is no appreciable tendency for the central strand C to migrate to the outside of the cord so as to produce a kink or the like, as shown at 30 in FIG. 4, projecting beyond the outer strands O of the multistrand cord.

While the practice of the present invention has been described with particular reference to seven-end textile cord, it is to be understood that the number of strands in the finished multistrand cord may be different from seven without departing from the spirit and scope of this invention.

Having described my invention, I claim:

1. In a method of making a multistrand textile cord on a 2-for-l twisting machine having a rotary spindle with a longitudinal passage and an outlet opening in its periphery at one end of said passage, a rotary cord wrap-around member connected to said spindle just beyond said outlet opening, a rotary flyer disk connected to said spindle just beyond said wrap-around member for guiding the cord as it balloons outwardly centrifugally, and guide means spaced axially from the flyer disk for receiving the cord at the Opposite end of its balloon, the improvement which comprises passing into said spindle passage a central strand which is pre-twisted in the same direction as the direction of twist imparted to the cord by the rotation of the spindle, wrap-around member and ilyer disk, and at the same time passing into the spindle passage a plurality of outer strands which are individually pre-twisted in the opposite direction of twist.

2. A method according to claim 1, wherein said plurality of outer strands consist of six outer strands which are individually pre-twisted in said opposite -direction of twist.

References Cited UNITED STATES PATENTS 2,008,075 7/l935 Kraft 57-58.65 2,055,037 9/1936 MacKinnon 57-144 2,056,470 10/1936 Kraft 57-58.65 2,834,178 5/1958 Klein 57-58.65 XR 3,158,984 12/1964 Butler 57l44 3,329,061 7/1967 Momoi 57-144 XR 3,383,849 5/1968 Stirling 57-144 MERVIN STEIN, Primary Examiner WERNER H. SCHROE-DER, Assistant Examiner U.S. Cl. X.R. 

